Answer:
-15a+d
Step-by-step explanation:
5a-20a+12d-11d
-15a+d
<span>Triangles exist:
</span>3 acute angles<span>
2 acute angles, 1 right angle
</span><span>2 acute angles, 1 obtuse angle
</span>
Triangles DON'T exist for:
<span>1 acute angle, 1 right angle, 1 obtuse angle
</span><span>1 acute angle, 2 obtuse angles</span>
Pythagorean stack i believe its 23 on the side
-10d^2 + 11d - 2
To find this, distribute the - to 7d^2 - d - 6.
This will give you a new equation of:
-3d^2 + 10d - 8 -7d^2 + d + 6
Combine like terms to get the answer above.
Hope this helps!